As discussed in Japanese Patent Application Laid-Open No. 2012-227602, there is a conventional imaging apparatus that is capable of coding captured image data and outputting the coded image data to an external device via a network. Among various types of image data coding methods, JPEG and MPEG4 are representative coding methods applicable to still images and H.264 is a representative coding method applicable to moving images.
For example, the JPEG and H.264 coding methods can be implemented by a network camera apparatus that encodes image data according to a coding method designated by a client apparatus and performs streaming processing for distributing the coded image data to the client apparatus via a network.
Further, standard protocols are conventionally used to establish common communication interfaces when a network camera apparatus communicates with a client apparatus via a network. An example of the conventionally known standard protocols is common standards formulated by Open Network Video Interface Forum (ONVIF).
The coding methods presently defined according to the ONVIF are JPEG applicable to still images and MPEG4 or H.264 applicable to moving images.
New versions of the network camera apparatus and the client apparatus, in which setting commands conforming to a new coding method (e.g., JPEG2000 or H.265) can be implemented, will be possibly introduced in the future to satisfy the needs for enhanced image quality and higher compression.
Therefore, installation of a new network camera apparatus brings a complicated situation in a network system, in which new and old network camera apparatuses are mixed with new and old client apparatuses. Therefore, a new network camera apparatus is required to maintain sufficient consistency in system implementation to provide an interface capable of maintaining adequate backward compatibility. In addition, subsidiary usage of existing commands may be recommended to reduce the number of newly added commands.